Occurrence of halogenated contaminants in inland and coastal fish from Ghana: Levels, dietary exposure assessment and human health implications

Abstract

Fish consumption is known to have several health benefits for humans. However, the accumulation of toxic contaminants, such as PCBs, PBDEs and HBCDs in fish could pose health hazards. These contaminants were measured in tilapia fish species collected from Ghana. Mean levels were PCBs (62ng/g lw), PBDEs (7.3ng/g lw) and HBCDs (1.2ng/g lw) and the predominance of CB-153, CB-138, CB-180, BDE-47 and α-HBCD is in concordance with scientific literature. The congener profiles of PBDEs and PCBs in the fish suggest that sources of Penta- and Deca-BDE technical mixtures as well as technical PCB mixture (Clophen A60) exist in Ghana, while textile operations and associated release of untreated wastewater are likely to be significant sources of HBCDs. Comparison of the results with some reported studies showed moderate contamination in Ghana although Ghana is a developing country in Africa. Concentrations of PCBs measured in all the specimens in this study were below the food safety guidelines issued by the Food and Drug Administration, USA and the European Commission. The calculated hazard index levels of the target contaminants were below the threshold value of one, indicating that the levels of the target contaminants do not seem to constitute a health risk via fish consumption, with regard to PCBs, PBDEs and HBCDs, based on the limited number of samples that was accounted for in this study. However, due to the continuous discharge of untreated effluents, follow up studies are warranted as the consumption of fish is the primary route of human exposure to PCBs. This maiden report on the status of PBDEs and HBCDs in fish from Ghana will contribute to the knowledge about environmental contamination by POPs in a less industrialized region of the world so far sparsely covered in the literature.